1. Technological Field
This invention relates to a flat panel display device having a flat display panel, made up of multiple display pixels, and a surface iluminant light source.
2. Prior Art
Flat panel display devises typified by liquid crystal display device have come to be used for various display devices such as personal computer and word processor display devices and television screens.
This kind of display generally comprises a flat display panel having a display area made up of multiple display pixels and a surface iluminant light source disposed behind the flat display panel.
In recent years, to make flat panel display devices thinner, instead of the conventional surface iluminant light source disposed directly underneath the flat display panel, edge-light type surface iluminant light sources have come to be used.
An edge-light type surface iluminant light source usually consists of a light-transmitting plate and a linear light source disposed near one side of the light-transmitting plate. The light-transmitting plate is for example made of acrylic resin and substantially flat and has an opaque scattering pattern formed on its rear side by printing. The linear light source is usually a fluorescent lamp comprising a cathode tube. Light from the linear light source is directed into the light-transmitting plate and is reflected and transmit inside the light-transmitting plate. Light reaching the scattering pattern on the light-transmitting plate is scattered and emerged through the main surface side of the light-transmitting plate.
With this kind of edge-light type surface iluminant light source, because the thickness of the surface iluminant light source can be made roughly the thickness of the light-transmitting plate, the flat panel display device can be made thinner.
In a flat panel display device, generally, a first frame on the display side of the flat panel display device together with a second frame holding the surface iluminant light source receives, sandwiches and fixes the flat display panel. In this way the surface iluminant light source is fixed to the flat display panel and the flat display panel is protected from external shocks.
FIG. 13 and FIG. 14 schematically show a typical example of a structure of an end part of a conventional flat panel display device in which a linear light source (1811) is disposed. In the drawings and the following description, the display side of the flat panel display device is the upper side thereof.
A vertical side wall (1521) of a first frame (1500) together with a vertical wall (1851) of a cross-sectionally L-shaped lamp cover (1850) forms a side wall of a flat panel display device (1000). Both of the vertical walls (1521, 1851) are flat sheets with straight edges, and their ends overlap with the lower end of the vertical side wall (1521) of the first frame on the outside. Screw holes are provided in the ends of the lamp cover (1850) and the lamp cover (1850) is fixed to the flat panel display device (1000) by screws (1853) being passed through these screw holes and screwed into threaded holes provided in a second frame (1600) at corners of the flat panel display device (1000). A first feed lead is connected to the end of a linear light source (1811) on an electrical feed supply side thereof, a second feed lead is connected to the other end and the second feed lead (1815) is led between the second frame (1600) and the vertical wall (1851) of the lamp cover.
Replacement of the linear light source (1811) is carried out by removing the screws (1853), pulling off the lamp cover (1850) downward pulling out the linear light source (1811) and the second feed lead (1815) and refitting them in the same way.
However, along with displays being made thinner as mentioned above their frames have also been being made smaller, and as a result of this the rigidity of the casing holding the flat display panel has been decreased. Furthermore, in recent years, to reduce the weight of displays there has been a tendency for the frame metal thickness to be reduced also, and if the rigidity of the casing holding the flat display panel falls further there is a possibility that the flat display panel will easily be damaged by shocks from outside.